Portion of a sleep collar



FIG. 1 is a perspective view of a portion of a sleep collar showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a front elevational view thereof shown in a coupled position and attached to a safety seat, the broken line showing of which is for illustrative purposes only and forms no part of the claimed design; and,

FIG. 4 is a perspective view of another embodiment thereof.

The broken line showing of the ends of each sleep collar support, the attachment straps, and the strip portions between the broken lines along the concave region of each support shown in FIGS. 1-3 form no part of the claimed design.

The broken line showing of the ends of each sleep collar support and the attachment straps shown in FIG. 4 forms no part of the claimed design. 

The ornamental design for a portion of a sleep collar, as shown and described. 